replace doc footer of all authors with link to AUTHORS

[orbeckst]

Over the last 2 years or so we had discussions about how to represent the effort of all authors. One point was that we should replace the "all author footer" on every page of the docs, which looks like this:

with a simpler "Copyright © 2025 - {current.year} The MDAnalysis Development Team (see AUTHORS for all names)" or something similar.

Shortening the footer would also make it easier to see the link to our Privacy Policy at the bottom of the page.

• This is a change that one of the core developer team should make as it ultimately relates to project policy. (I just tentatively assigned people to indicate that this is not an issue that someone should just pick up.)
• I remember that we said we would do the change for 3.0; however, if @MDAnalysis/coredevs do not oppose we can also do this sooner (i.e., for 2.8).

For background: I recently did the same for alchemlyb in alchemistry/alchemlyb#384 — I am linking the PR because it wasn't entirely trivial to change the footer.

[richardjgowers]

Yeah no harm in this

[hmacdope]

Happy with this also.